code: def check_indiscernibility(method, hist):
      """a must be unique, and a is identical to a if and only if dist(a,a)=0"""
  
      assert within_tolerance(method(hist, hist), 0.0)
  
file_path: medpy/tests/metric_/histogram.py
imports: import numpy
  from hypothesis import given, strategies, assume, Verbosity, note, event
  from hypothesis import settings
  from medpy.metric import histogram
label_desc: Use image node_id 4 for calling a global function with example usage: check_indiscernibility(method, hist) without return types